Security caps for ball-lock pins, a.k.a. 'Pip-pins', should you loose one. These are to buy separately, if you are ordering the pip pins as well you can just tick the 'With Caps' option on the Pip-pin page.

Pair (2) sets of wheel halves, hubs and bag (red bag shown). These parts assemble to make two landing wheels to fit on an airfoil speedbar. The hubs are available in two designs; to fit aerofoil aluminium speed bars:
Avian, Moyes, Airborne section or
Wills Wing section.